Systems and methods for crash determination with noise filtering

ABSTRACT

Embodiments of the invention include a vehicle telematics system including a telematics device and a remote server system, wherein the telematics device obtains sensor data from at least one sensor installed in a vehicle, calculates peak resultant data based on the sensor data, generates crash score data based on the peak resultant data and a set of crash curve data for the vehicle, and provides the obtained sensor data when the crash score data exceeds a crash threshold to the remote server system and the remote server system obtains vehicle sensor data and vehicle identification data from the vehicle telematics device, calculates resultant change data and absolute speed change data based on the obtained sensor data and/or the vehicle identification data, and generates crash occurred data when the resultant change data exceeds a first threshold value and when the absolute speed change data is below a second threshold value.

CROSS-REFERENCE TO RELATED APPLICATIONS

The current application is a continuation of U.S. patent application Ser. No. 16/551,465, filed Aug. 26, 2019, entitled “Systems and Methods Crash Determination with Noise Filtering” to Jenkins et al., which is a continuation of U.S. patent application Ser. No. 15/241,517, filed Aug. 19, 2016, now U.S. Pat. No. 10,395,438, entitled “Systems and Methods for Crash Determination with Noise Filtering” to Jenkins et al., the disclosure of each of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to determining vehicle operational status and more specifically to determining if a vehicle has been involved in an accident.

BACKGROUND

A Global Positioning System (GPS) is a space-based global navigation satellite system that utilizes a network of geo-synchronous satellites that can be utilized by a GPS receiver to determine its location. Many telematics systems incorporate a Global Positioning System (GPS) receiver that can be used to obtain the location of a vehicle at a certain measured time. Using the signals received by the GPS receiver, the heading information of the vehicle can be determined. A GPS receiver can determine velocity information in a variety of ways including, but not limited to, measuring the Doppler shift of the received signals and by comparing the location of a vehicle at a plurality of measured times. The acceleration of the vehicle can be determined as the change in speed divided by the time between the measurements. A GPS receiver's ability to determine acceleration can be limited due to the dependence of the measurement upon factors such as, but not limited to, reception and satellite availability. In addition to location information, a GPS receiver can also be configured to provide time data. However, measurements determined via a GPS receiver can contain errors that affect the accuracy of the measured information. In particular, GPS signals are vulnerable to signal delays, inconsistencies of atmospheric conditions that affect the speed of the GPS signals as they pass through the Earth's atmosphere, and multipath distortions. Additionally, other factors not listed above can influence GPS signals and result in measurement errors.

Telematics is the integrated use of telecommunications and informatics. Telematics units are installed in vehicles to provide a variety of telematics functionality in the vehicle. This functionality includes, but is not limited to, emergency warning systems, navigation functionality, safety warnings, and automated driving assistance. Telematics units are also capable of recording data related to the operation of the vehicle and providing that information for analysis, whether in real-time or during a time when the vehicle is being serviced. This information can be used in a variety of applications, such as fleet tracking, shipment tracking, insurance calculations, and in vehicle management and service.

SUMMARY OF THE INVENTION

Systems and methods for crash determination in accordance with embodiments of the invention are disclosed. In one embodiment, a vehicle telematics device includes a processor and a memory connected to the processor and storing a crash determination application, wherein the processor, on reading the crash determination application, is directed to obtain sensor data from at least one sensor installed in a vehicle, calculate peak resultant data based on the sensor data, where the peak resultant data describes the acceleration of the vehicle over a first time period, generate crash score data based on the peak resultant data and a set of crash curve data for the vehicle, where the crash score data describes the likelihood that the vehicle was involved in a crash based on the characteristics of the vehicle and the sensor data, and provide the obtained sensor data when the crash score data exceeds a crash threshold to a remote server system.

In another embodiment of the invention, the at least one sensor includes an accelerometer.

In an additional embodiment of the invention, the crash curve data is based on vehicle data including a vehicle identification number associated with the vehicle.

In yet another additional embodiment of the invention, the crash curve data is dynamically determined based on vehicle data describing a weight of the vehicle.

In still another additional embodiment of the invention, the at least one sensor includes a weight sensor.

In yet still another additional embodiment of the invention, the vehicle telematics system further includes a communications interface and the vehicle telematics unit obtains the sensor data using the communications interface.

In yet another embodiment of the invention, the set of crash curve data is provided by the remote server system.

In still another embodiment of the invention, the remote server system includes a processor and a memory storing a crash analysis application and the processor of the remote server system, on reading the crash analysis application, is directed to obtain vehicle sensor data from the vehicle telematics device, obtain vehicle identification data from the vehicle telematics device, calculate resultant change data based on the obtained sensor data and the vehicle identification data, and generate crash occurred data when the resultant change data exceeds a threshold value.

In yet still another embodiment of the invention, the processor of the remote server system is further directed to provide notification data including the crash occurred data.

In yet another additional embodiment of the invention, the crash score data is generated by calculating peak resultant data based on the obtained sensor data and calculating the crash score data based on a duration of time in which the peak resultant data exceeds the crash curve data.

Still another embodiment of the invention includes a method for determining if a vehicle has been involved in a crash by obtaining sensor data from at least one sensor installed in a vehicle using a vehicle telematics device, where the vehicle telematics device includes a processor and a memory, calculating peak resultant data based on the sensor data using the vehicle telematics device, where the peak resultant data describes the acceleration of the vehicle over a first time period, generating crash score data based on the peak resultant data and a set of crash curve data for the vehicle using the vehicle telematics device, where the crash score data describes the likelihood that the vehicle was involved in a crash based on the characteristics of the vehicle and the sensor data, and providing the obtained sensor data when the crash score data exceeds a crash threshold to a remote server system using the vehicle telematics device.

In yet another additional embodiment of the invention, the at least one sensor includes an accelerometer.

In still another additional embodiment of the invention, the crash curve data is based on vehicle data including a vehicle identification number associated with the vehicle.

In yet still another additional embodiment of the invention, the crash curve data is dynamically determined based on vehicle data describing a weight of the vehicle.

In yet another embodiment of the invention, the at least one sensor includes a weight sensor.

In still another embodiment of the invention, the vehicle telematics system further includes a communications interface and the vehicle telematics unit obtains the sensor data using the communications interface.

In yet still another embodiment of the invention, the set of crash curve data is provided by the remote server system.

In yet another additional embodiment of the invention, the method further includes obtaining vehicle sensor data from the vehicle telematics device using a remote server system including a processor and a memory, obtaining vehicle identification data from the vehicle telematics device using the remote server system, calculating resultant change data based on the obtained sensor data and the vehicle identification data using the remote server system, and generating crash occurred data when the resultant change data exceeds a threshold value using the remote server system.

In still another additional embodiment of the invention, the method further includes providing notification data including the crash occurred data using the remote server system.

In yet still another additional embodiment of the invention, the crash score data is generated by calculating peak resultant data based on the obtained sensor data using the vehicle telematics device and calculating the crash score data based on a duration of time in which the peak resultant data exceeds the crash curve data using the vehicle telematics device.

Yet another embodiment of the invention includes a vehicle telematics system including a telematics device including a processor and a memory storing a crash determination application and a remote server system including a processor and a memory storing a crash analysis application, wherein the processor of the telematics device, on reading the crash determination application, is directed to obtain sensor data from at least one sensor installed in a vehicle, calculate peak resultant data based on the sensor data, where the peak resultant data describes the acceleration of the vehicle over a first time period, generate crash score data based on the peak resultant data and a set of crash curve data for the vehicle, where the crash score data describes the likelihood that the vehicle was involved in a crash based on the characteristics of the vehicle and the sensor data, and provide the obtained sensor data when the crash score data exceeds a crash threshold to a remote server system, and wherein the processor of the remote server system, on reading the crash analysis application, is directed to obtain vehicle sensor data from the vehicle telematics device, obtain vehicle identification data from the vehicle telematics device, calculate resultant change data based on the obtained sensor data and the vehicle identification data, calculate absolute speed change data based on the obtained sensor data, and generate crash occurred data when the resultant change data exceeds a first threshold value and when the absolute speed change data is below a second threshold value.

In yet another additional embodiment of the invention, the at least one sensor includes an accelerometer.

In still another additional embodiment of the invention, the crash curve data is based on vehicle data including a vehicle identification number associated with the vehicle.

In yet still another additional embodiment of the invention, the crash curve data is dynamically determined based on vehicle data describing a weight of the vehicle.

In yet another embodiment of the invention, the at least one sensor includes a weight sensor.

In still another embodiment of the invention, the vehicle telematics system further includes a communications interface and the vehicle telematics unit obtains the sensor data using the communications interface.

In yet still another embodiment of the invention, the set of crash curve data is provided by the remote server system.

In yet another additional embodiment of the invention, the absolute speed change data is calculated by taking the absolute value of the integral of the sensor data indicating acceleration data in a forward vector.

In still another additional embodiment of the invention, the absolute speed change data is calculated by taking the absolute value of the integral of the sensor data indicating acceleration data in a lateral vector.

In yet still another additional embodiment of the invention, the crash score data is generated by calculating peak resultant data based on the obtained sensor data and calculating the crash score data based on a duration of time in which the peak resultant data exceeds the crash curve data.

Still another embodiment of the invention includes a method for determining if a vehicle has been involved in a crash including obtaining sensor data from at least one sensor installed in a vehicle using a vehicle telematics device, where the vehicle telematics device includes a processor and a memory, calculating peak resultant data based on the sensor data using the vehicle telematics device, where the peak resultant data describes the acceleration of the vehicle over a first time period, generating crash score data based on the peak resultant data and a set of crash curve data for the vehicle using the vehicle telematics device, where the crash score data describes the likelihood that the vehicle was involved in a crash based on the characteristics of the vehicle and the sensor data, providing the obtained sensor data when the crash score data exceeds a crash threshold to a remote server system using the vehicle telematics device, where the remote server system includes a processor and a memory, obtaining vehicle sensor data from the vehicle telematics device using the remote server system, obtaining vehicle identification data from the vehicle telematics device using the remote server system, calculating resultant change data based on the obtained sensor data and the vehicle identification data using the remote server system, calculating absolute speed change data based on the obtained sensor data using the remote server system, and generating crash occurred data when the resultant change data exceeds a threshold value and when the absolute speed change data is below a second threshold value using the remote server system.

In yet another additional embodiment of the invention, the at least one sensor includes an accelerometer.

In still another additional embodiment of the invention, the crash curve data is based on vehicle data including a vehicle identification number associated with the vehicle.

In yet still another additional embodiment of the invention, the crash curve data is dynamically determined based on vehicle data describing a weight of the vehicle.

In yet another embodiment of the invention, the at least one sensor includes a weight sensor.

In still another embodiment of the invention, the vehicle telematics system further includes a communications interface and the vehicle telematics unit obtains the sensor data using the communications interface.

In yet still another embodiment of the invention, the set of crash curve data is provided by the remote server system.

In yet another additional embodiment of the invention, the absolute speed change data is calculated by taking the absolute value of the integral of the sensor data indicating acceleration data in a forward vector.

In still another additional embodiment of the invention, the absolute speed change data is calculated by taking the absolute value of the integral of the sensor data indicating acceleration data in a lateral vector.

In yet still another additional embodiment of the invention, the crash score data is generated by calculating peak resultant data based on the obtained sensor data using the vehicle telematics device and calculating the crash score data based on a duration of time in which the peak resultant data exceeds the crash curve data using the vehicle telematics device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual illustration of a crash determination system in accordance with an embodiment of the invention.

FIG. 2A is a conceptual illustration of a vehicle telematics device in accordance with an embodiment of the invention.

FIG. 2B is a conceptual illustration of a remote server system in accordance with an embodiment of the invention.

FIG. 3 is a flow chart illustrating a process for determining the occurrence of a crash event in accordance with an embodiment of the invention.

FIG. 4 is a flow chart illustrating a process for a local crash analysis in accordance with an embodiment of the invention.

FIG. 5 is a flow chart illustrating a process for a remote crash analysis in accordance with an embodiment of the invention.

FIG. 6 is a flow chart illustrating a process for filtering noise in a crash analysis in accordance with an embodiment of the invention.

FIGS. 7A-B are conceptual illustrations of data measured and calculated in a variety of potential crash events in accordance with embodiments of the invention.

DETAILED DESCRIPTION

Turning now to the drawings, systems and methods for determining if a vehicle has been involved in a crash in accordance with embodiments of the invention are disclosed. Many vehicles are equipped with a variety of safety systems, such as airbags and other crash-related protections. These safety systems activate when a variety of sensors installed in the car sense that a crash has occurred, thereby causing the safety system (i.e. the airbags) to deploy. The safety systems are single-vehicle devices specifically calibrated and designed for the specific make and model of vehicle in which they are installed. Each vehicle has different characteristics, such as weight and sensor installation location, which can strongly affect the sensor information that would indicate a crash for which airbags should deploy and each of the safety systems are extensively tested, by both the vehicle manufacturer and the federal government, to determine the proper operation for firing the airbag. Due to the need to quickly deploy the airbags in the event of a crash, these safety systems need to determine if crash has occurred in 2-3 milliseconds as the airbags are deployed within 10-50 milliseconds of the sensors determining a crash. However, the safety systems do not record information about what was occurring at the time of the crash and, especially due to the speed required to deploy the airbag or other safety system, do not have sufficient time or capability to analyze the information generated before and/or during the crash.

Crash determination systems in accordance with embodiments of the invention are capable of capturing data describing the operation of the vehicle before, during, and after a potential crash event. The crash determination systems can also analyze the captured data to determine if a crash has occurred. This type of analysis cannot routinely be performed using the safety systems in the vehicle as the crash has ended by the time crash detection has occurred and the computational and memory capabilities of the integrated safety systems can be a limiting factor. The post-crash analysis performed using a vehicle telematics system can discriminate between impacts (minor bumps, potholes, etc. . . . ) and actual crash events. Crash determination systems can perform a crash analysis in a variety of ways, including comparing a pre-set value against acceleration readings and by comparing the magnitude of the acceleration event against crash curve data, as appropriate to the requirements of specific embodiments of the invention. Many safety systems installed in vehicles utilize a crash curve to determine if a crash has occurred; however, these systems are limited in that the crash curve must be pre-set for the specific vehicle in which the safety system is installed and is highly dependent on the location in which the safety sensors are installed as described above.

Crash determination systems include vehicle telematics devices that are installed in a vehicle aftermarket. The vehicle telematics devices can be installed in a variety of locations depending on the make, model, and/or year of the vehicle and the specific installation location can vary between cars of the same make, model, and/or year. In many instances, vehicle telematics devices are installed in a location in a vehicle where data obtained from sensors installed in the vehicle, such as the airbag sensors, and/or data from a diagnostic connector for an onboard vehicle data bus, is unavailable to the vehicle telematics device. In this way, the crash determination devices provide a universal system for analyzing crash events. In several embodiments, the vehicle telematics device automatically determines crash curve data for the specific vehicle in which it is installed. Crash determination systems can also employ a two-stage analysis of the crash data. As is described in more detail below, a vehicle telematics device can obtain data during operation of the vehicle and/or perform a first stage analysis to determine if it is likely that a crash has occurred. The data can also be transmitted to a remote server system for a more detailed analysis. In this way, crash determination systems can differentiate between crash and non-crash events and provide a variety of data to dynamically determine crash curve data across many classes of vehicles.

A variety of installation and operational conditions can affect the accuracy of the data captured and processed by the crash determination systems. The errors introduced by these conditions can result in false positives in the crash determination processes. For example, in a variety of embodiments a vehicle telematics unit is connected to a diagnostic connector (e.g. an OBD II port) in a vehicle. Different makes and models of vehicles can have diagnostic connectors having different levels of stiffness so that, during the operation of the vehicle, the vehicle telematics unit moves and/or vibrates. This movement and/or vibration (e.g. noise) can cause the sensors in the vehicle telematics unit to generate sensor data that exceeds what would be expected for a particular event. These events can include when a vehicle encounters a pothole, a rumble strip, an uneven road, and/or any other condition as appropriate to the requirements of specific applications of embodiments of the invention. The noise present in the sensor data can then result in the crash determination system identifying a crash when no such crash occurred, such as indicating a crash when a vehicle drives over a rumble strip on the highway. A variety of filtering processes can be performed by the crash determination systems when a crash event has been identified in order to identify false positives, thereby improving the ability of the crash determination system to process sensor data and identify crash events. It should be noted that any data generated by the sensors can exhibit behavior indicative of a false positive crash event, not just sensor data having noise introduced by the movement of a vehicle telematics device in a vehicle diagnostic port, can be identified and/or filtered in accordance with the requirements of specific applications of embodiments of the invention.

In a variety of embodiments, the operational state of a vehicle is utilized in determining if a crash has occurred. That is, many crash determination systems in accordance with embodiments of the invention analyze crashes that occur while a vehicle is in operation, not while parked. In a number of embodiments, vehicle ignition state (i.e. the operational status of the vehicle) is ascertained by monitoring the vehicle for signs indicative of the vehicle ignition state without directly connecting to the vehicle ignition line. Information indicative of vehicle ignition state (i.e. vehicle status data) can be ascertained by observing characteristics of the vehicle including but not limited to the power supplied by the vehicle, vehicle vibration, communications on an OBD II or other vehicle data bus line, and/or vehicle position information. In many embodiments, multiple different types of information are combined to ascertain the vehicle ignition state. Systems and methods for using a vehicle telematics device added to the vehicle after the manufacture of the vehicle without a direct connection to the vehicle ignition line that can be utilized to determine ignition state information in accordance with embodiments of the invention are described in U.S. Pat. No. 8,489,271, titled “Systems and Methods for Virtual Ignition Detection” and issued Jul. 16, 2013, the disclosure of which is hereby incorporated by reference in its entirety.

In accordance with many embodiments of the invention, vehicle telematics devices are equipped with one or more sensors capable of determining the speed and/or acceleration of the vehicle. Vehicle speed can be calculated using information provided by a Global Position System (GPS) receiver by dividing the distance traveled by the GPS receiver by the time between measurements taken by the GPS receiver. In several embodiments, the GPS receiver is configured to determine velocity information using the signals received by the GPS receiver. A GPS receiver can determine velocity information in a variety of ways in accordance with embodiments of the invention, including, but not limited to, measuring the Doppler shift of the received signals. The differences in vehicle speed between measurements taken by the GPS receiver can be used to determine acceleration data for the vehicle. GPS receivers are also capable of determining the location of a vehicle and/or the heading of the vehicle utilizing the received signals. A variety of devices other than GPS receivers can be utilized in vehicles to determine information related to the vehicle, such as speed, acceleration, and heading. For example, acceleration information for a vehicle can be measured using an accelerometer, which are often installed on a vehicle or mobile device. Heading information can be determined using a compass. Vibration information can be determined using acceleration information taken using an acceleration sensor. In several embodiments, vehicle telematics systems are calibrated to accurately determine speed and/or acceleration data. Systems and methods for calibrating a 3-axis accelerometer which can be utilized to determine vibration information in accordance with a variety of embodiments of the invention are disclosed in U.S. Pat. No. 9,217,757, titled “Systems and Methods for 3-Axis Accelerometer Calibration” and issued Dec. 22, 2015, the entirety of which is hereby incorporated by reference.

The data captured by a vehicle telematics device can also be utilized to accurately determine the location at which a crash occurred. In a number of embodiments, the determination of the ignition status of a vehicle and/or the start of a trip can be utilized in a variety of ways, such as determining particular events that occur during the operation of the vehicle. Systems and methods for determining the location of events that can be utilized in accordance with embodiments of the invention are described in U.S. Pat. No. 9,406,222, titled “Systems and Methods for Location Reporting of Detected Events in Vehicle Operation” and issued Aug. 2, 2016, the disclosure of which is hereby incorporated by reference in its entirety.

Systems and methods for crash determination, including crash determination with noise filtering, in accordance with embodiments of the invention are described in more detail below.

Crash Determination Systems

Crash determination systems in accordance with embodiments of the invention can obtain a variety of data describing the status of a vehicle and determine when the vehicle has been involved in a crash. A conceptual diagram of a crash determination system in accordance with an embodiment of the invention is shown in FIG. 1. The crash determination system 100 includes a vehicle telematics device 110 that can communicate with a remote server system 130, a vehicle data bus 122, and/or an input/output (I/O) interface 124 as appropriate to the requirements of specific applications of embodiments of the invention. In a variety of embodiments, the vehicle telematics device 110 communicates with the remote server system 130 via a network 120. In a variety of embodiments, the network 120 is the Internet. In many embodiments, the network 120 is any wired or wireless network, such as a cellular network, between the vehicle telematics device 110 and the remote server system 130. In a number of embodiments, the remote server system 130 implemented using a single server system. In several embodiments, the remote server system 130 is implemented using multiple server systems.

In a variety of embodiments, the vehicle telematics device 110 is installed in a vehicle having a vehicle data bus 122. In several embodiments, the vehicle telematics device 110 is installed in a vehicle diagnostic connector that provides access to the vehicle data bus 122. The vehicle telematics device 110 can obtain data from any of a variety of vehicle devices connected to the vehicle data bus 122 utilizing any of a variety of techniques as appropriate to the requirements of specific applications of embodiments of the invention. Vehicle devices can include, but are not limited to, engine sensors, electronic control unit (ECU) devices, alternator sensors, vibration sensors, voltage sensors, oxygen sensors, Global Positioning System (GPS) receivers, ignition devices, weight sensors, and/or acceleration determination devices. Systems and methods for connecting to a vehicle data bus that can be utilized in accordance with embodiments of the invention are described in SAE J1978, titled “OBD II Scan Tool,” first published by SAE International of Troy, Mich. on Mar. 1, 1992 and last updated Apr. 30, 2002. Systems and methods for obtaining data from devices connected to a vehicle data bus are described in SAE J1979, titled “E/E Diagnostic Test Modes,” first published by SAE International on Dec. 1, 1991 and last updated Aug. 11, 2014. The disclosures of SAE J1978 and SAE J1979 are hereby incorporated by reference in their entirety. In a number of embodiments, the vehicle telematics device is connected directly to one or more sensors within the vehicle and/or does not utilize the vehicle data bus 122.

The vehicle telematics device 110 can include any of a variety of sensors and/or devices, including those described above with respect to the vehicle data bus and those described in more detail below, to obtain data regarding the status of the vehicle. This data can be utilized in a variety of crash determination processes to determine if the vehicle has been involved in a crash as described in more detail below. The vehicle telematics device 110 can also communicate with any of a variety of sensors and/or devices using the I/O interface 124. The I/O interface 124 can be any connection, including wired and wireless connections, as appropriate to the requirements of specific applications of embodiments of the invention. In several embodiments, the vehicle telematics device 110 is capable of executing scripts to read data and/or perform particular processes. These scripts can be pre-loaded on the device and/or obtained from the remote server system 130, vehicle data bus 122, and/or the I/O interface 124 as appropriate to the requirements of specific applications of embodiments of the invention. The vehicle telematics device 110 can be self-powered and/or connected into the electrical system of the vehicle in which the vehicle telematics device 110 is installed. In a variety of embodiments, the vehicle telematics device is powered via the vehicle data bus 122 and/or the I/O interface 124. In many embodiments, the vehicle telematics device 110 utilizes a Global Positioning System (GPS) receiver in order to determine the location, speed, and/or acceleration of the vehicle. However, it should be noted that any location-determining techniques, such as cellular tower triangulation, wireless network geolocation techniques, and dead reckoning techniques, could be utilized as appropriate to the requirements of specific applications of embodiments of the invention.

In a variety of embodiments, the vehicle telematics device 110 and/or remote server system 130 provides a user interface allowing for visualizing and interacting with the data. In several embodiments, the vehicle telematics device 110 and/or remote server system 130 provides an interface, such as an application programming interface (API) or web service that provides some or all of the data to third-party systems for further processing. Access to the interface can be open and/or secured using any of a variety of techniques, such as by using client authorization keys, as appropriate to the requirements of specific applications of the invention.

Although a specific architecture of a crash determination system in accordance with embodiments of the invention are discussed above and illustrated in FIG. 1, a variety of architectures, including sensors and other devices and techniques not specifically described above, can be utilized in accordance with embodiments of the invention. Furthermore, the processes described herein can be performed using any combination the vehicle telematics devices and/or the remote server systems as appropriate to the requirements of specific applications of embodiments of the invention.

Vehicle Telematics Devices

Vehicle telematics devices in accordance with embodiments of the invention can obtain data regarding the status of a vehicle and determine if the vehicle has been involved in a crash. A conceptual illustration of a vehicle telematics device in accordance with an embodiment of the invention is shown in FIG. 2A. The vehicle telematics device 200 includes a processor 210 in communication with memory 230. The vehicle status determination device 200 can also include one or more communication interfaces 220 capable of sending and receiving data. In a number of embodiments, the communication interface 220 is in communication with the processor 210, the memory 230, and/or the sensor device(s) 240. In several embodiments, the memory 230 is any form of storage configured to store a variety of data, including, but not limited to, a crash determination application 232, crash curve data 234, vehicle data 236, and sensor data 238. In many embodiments, the crash determination application 232, crash curve data 234, vehicle data 236, and/or sensor data 238 are stored using an external server system and received by the vehicle telematics device 200 using the communications interface 220. Sensor devices 240 can include RPM sensors, voltage sensors, GPS receivers, noise sensors, vibration sensors, acceleration sensors, weight sensors, and any other device capable of measuring data regarding a vehicle as appropriate to the requirements of specific applications of embodiments of the invention. Sensor devices 240 can be included within the vehicle telematics device 200 and/or located external to the vehicle telematics device 200. The vehicle telematics 200 can communicate with external sensor devices using the communications interface 220, such as via a vehicle data bus, I/O interface, and/or a network connection as appropriate to the requirements of specific applications of embodiments of the invention.

Remote server systems in accordance with embodiments of the invention can obtain data regarding the status of a vehicle and determine if the vehicle has been involved in a crash. A conceptual illustration of a remote server system in accordance with an embodiment of the invention is shown in FIG. 2B. The remote server system 250 includes a processor 252 in communication with memory 260. The remote server system 250 can also include one or more communication interfaces 254 capable of sending and receiving data. In a number of embodiments, the communication interface 254 is in communication with the processor 252 and/or the memory 260. In several embodiments, the memory 260 is any form of storage configured to store a variety of data, including, but not limited to, a crash analysis application 262, crash curve data 264, vehicle identification data 266, vehicle sensor data 268, and/or historical data 270. In many embodiments, the crash analysis application 262, crash curve data 264, vehicle identification data 266, vehicle sensor data 268, and/or historical data 270 are stored using an external server system and received by the remote server system 250 using the communications interface 254.

The processor 210 and processor 252 can be directed, by the vehicle telematics application 232 and the crash analysis application 262 respectively, to perform a variety of crash determination processes. Crash determination processes can include obtaining data from a variety of sensor devices, determining data regarding the state of the vehicle, and using the vehicle data and/or crash curve data to determine if the vehicle has been involved in a crash. A number of crash determination processes that can be performed in accordance with embodiments of the invention are described in more detail below.

Although specific architectures for vehicle telematics devices and remote server systems in accordance with embodiments of the invention are conceptually illustrated in FIGS. 2A-B, any of a variety of architectures, including those that store data or applications on disk or some other form of storage and are loaded into memory at runtime, can also be utilized. Additionally, any of the data utilized in the system can be cached and transmitted once a network connection (such as a wireless network connection via the communications interface) becomes available. In a variety of embodiments, a memory includes circuitry such as, but not limited to, memory cells constructed using transistors, that are configured to store instructions. Similarly, a processor can include logic gates formed from transistors (or any other device) that dynamically perform actions based on the instructions stored in the memory. In several embodiments, the instructions are embodied in a configuration of logic gates within the processor to implement and/or perform actions described by the instructions. In this way, the systems and methods described herein can be performed utilizing both general-purpose computing hardware and by single-purpose devices.

Crash Detection

As described above, crash determination processes can include determining if a vehicle has been involved in a crash. In several embodiments, the crash determination processes include determining an appropriate threshold value and/or crash curve to be utilized in the crash determination process. Once a threshold value and/or crash curve has been determined for the vehicle, a variety of sensor data can be utilized to calculate crash score data describing the likelihood that the vehicle has been involved in a crash. In a variety of embodiments, the crash score data is calculated by determining if and/or how long the peak resultant of the acceleration of the vehicle exceeds a threshold value as described in more detail below. If the crash score data is indicative of a potential crash, the sensor data and/or vehicle identification data can be provided to a remote server system for a second stage analysis, also described in more detail below.

In a number of embodiments, the threshold value is pre-determined and/or determined dynamically. In a variety of embodiments, the threshold value is a crash curve defining a variable threshold value based on the characteristics of the vehicle and/or the measured sensor data. The characteristics of the vehicle can be described using vehicle identification data including any of a vehicle identification number, the weight of the vehicle, the length of the vehicle, the width of the vehicle, the wheelbase of the vehicle, the height of the vehicle, weight map data describing the distribution of weight throughout the vehicle, location data, and any other data as appropriate to the requirements of specific applications of embodiments of the invention. The threshold value can be determined using a vehicle telematics device and/or obtained from a remote server system as appropriate to the requirements of specific embodiments of the invention.

In a variety of embodiments, the threshold value is based on the location in which the telematics unit and/or the sensor devices are installed in the vehicle. In many embodiments, the threshold value is based on the weight of the vehicle. In those embodiments where a threshold value and/or a crash curve has not been defined for a specific vehicle, the characteristics of the vehicle can be utilized to dynamically generate and/or select a threshold value and/or crash curve that is appropriate to the specific vehicle. By way of example, the weight, height, length, and wheelbase of the vehicle can be utilized to determine a class of vehicle (i.e. small/medium/large and/or sedan/coupe/SUV/tractor/trailer) and a threshold value and/or crash curve can be selected based on previously measured events for other vehicles having a similar weight, height, length, and wheelbase. In several embodiments, several threshold values and/or crash curves can be combined to generate an appropriate threshold value and/or crash curve for the specific vehicle.

In many embodiments, the distribution of weight throughout the vehicle is utilized to determine the appropriate threshold value and/or crash curve. A weight map describing the distribution of weight can be generated based on the standard weight for the vehicle (e.g. the weight of the vehicle as provided by the manufacturer) modified by the removal and/or addition of elements to the vehicle. These modifications can include, but are not limited to, the weight of the occupants of the vehicle, the weight of any equipment added to the vehicle, the weight of any equipment removed from the vehicle, and any cargo carried in the vehicle. In several embodiments, the vehicle telematics system installed in the vehicle communicates with one or more weight sensors installed throughout the vehicle to obtain the weight of the vehicle at one or more locations within the vehicle. These weight sensors can be installed anywhere as appropriate to the requirements of specific embodiments of the invention, including in the seats of the vehicle, the trunk of the vehicle, and near the wheels and/or suspension of the vehicle. The vehicle telematics unit can communicate with the weight sensors in any manner as appropriate to the requirements of specific applications of embodiments of the invention, including via wired and/or wireless communication interfaces and onboard diagnostic systems. The weight map can include a scalar value indicating the total weight of the car and/or subdivide the vehicle to two or more regions and describe the weight in each of the regions. For example, the car can be divided into a front half and a back half, into quarters (drivers front, drivers rear, passenger front, passenger rear), into thirds (hood, passenger compartment, trunk), or any other set of regions as appropriate to the requirements of specific applications of embodiments of the invention.

Turning now to FIG. 3, a process for crash detection and analysis in accordance with an embodiment of the invention is shown. The process 300 can include identifying (310) vehicle data and obtaining (312) crash curve data. Sensor data is measured (314) and crash score data is calculated (316). When a crash threshold is reached (318), data can be provided (320) and analyzed (322).

Specific processes for detecting crashes in accordance with embodiments of the invention are described above and shown with respect to FIG. 3; however, any number of processes, including those that utilize different combinations of data than the examples described above, can be utilized as appropriate to the requirements of a specific application in accordance with embodiments of the invention. Techniques for local and remote crash analysis in accordance with embodiments of the invention are described in more detail below.

Local Crash Analysis

A variety of crash determination processes include performing a first stage analysis to determine if a vehicle has been involved in a crash. In several embodiments, the first stage analysis is performed using a vehicle telematics device installed in a vehicle. In many embodiments, the first stage analysis includes calculating peak resultant data from acceleration data obtained using acceleration sensors and comparing the peak resultant data to a crash curve for the vehicle. As described above, a variety of sensors can be utilized to obtain the sensor data utilized to perform the crash determination processes. In many embodiments, the sensors include an accelerometer capable of measuring acceleration data along a forward (x) vector and a lateral (y) vector. However, it should be noted that any number of sensors, including multiple single-vector accelerometers oriented along varying vectors, can be utilized to obtain the sensor data as appropriate to the requirements of specific applications of embodiments of the invention. The acceleration data can be utilized to calculate the peak resultant of the acceleration signals for the duration of the potential crash event. In several embodiments, the peak resultant is measured as a weight unit per mass of the vehicle along a particular vector. In a number of embodiments, the peak resultant (PeakR(xy)) for acceleration data measured in a forward (x) and lateral (y) vector can be calculated using the following equation:

PeakR(xy)=√{square root over (Xacceleration²+Yacceleration²)}

where Xacceleration is the measured acceleration along the forward vector and Y acceleration is the measured acceleration along the lateral vector. It should be noted that some (e.g. a subset) or all of the acceleration samples can be utilized to determine the peak resultant as appropriate to the requirements of specific applications of embodiments of the invention.

In the event that the peak resultant exceeds a threshold value for one or more of the measured axes then a crash event can be indicated. In several embodiments, a number of acceleration samples over a period of time are used to calculate the peak resultant over the time period. When the peak resultant exceeds the threshold value for the time period a potential crash event is indicated. The threshold value can be a pre-determined value, determined dynamically based on the characteristics of the vehicle, and/or a crash curve as described above. The crash curve for the vehicle can be pre-determined and/or determined dynamically based on the characteristics of the vehicle as appropriate to the requirements of specific applications of embodiments of the invention. In several embodiments, the crash curve data is obtained from a remote server system based on the vehicle identification data provided by a vehicle telematics unit.

If the first stage analysis determines that a crash may have occurred, the vehicle sensor data and data identifying the vehicle can be utilized to perform a second stage analysis, described in more detail below. This second stage analysis can be performed using the vehicle telematics unit and/or the data can be provided to a remote server system for processing as appropriate to the requirements of specific applications of embodiments of the invention. In a variety of embodiments, filtering processes are applied when a potential crash event is indicated. These filtering processes can be utilized to identify false positive crash events and thereby not transmit data to a remote server system. This can improve the functionality of a vehicle telematics device by improving the accuracy of first stage analysis and saving processing time, bandwidth, and/or reducing the amount of data transmitted during the crash analysis processes. Any of a variety of techniques can be utilized to filter the potential crash events as appropriate to the requirements of specific applications of embodiments of the invention, including those described below with respect to FIG. 6.

Turning now to FIG. 4, a process for local crash analysis in accordance with an embodiment of the invention is shown. The process 400 includes obtaining (410) sensor data, calculating (412) peak resultant data, and determining (414) threshold exceeded data. When a threshold is reached (416), data can be provided (418) to any of a variety of systems, including remote server systems as appropriate to the requirements of specific applications of embodiments of the invention.

Although specific processes for local crash analysis in accordance with embodiments of the invention are described above and shown with respect to FIG. 4, any number of processes, including those that use alternative criteria for determining if a crash has potentially occurred or accumulate sensor data using any of a variety of data recordation techniques, can be utilized as appropriate to the requirements of a specific application in accordance with embodiments of the invention.

Remote Crash Analysis

In many embodiments, crash determination processes include performing a second stage analysis to determine if a vehicle has been involved in a crash. In a number of embodiments, the second stage analysis is performed by a remote server system having the time and/or computing resources exceeding those present in a vehicle telematics device, thereby allowing more complex analyses to be performed. Vehicle sensor data can be obtained and utilized to calculate the resultant change in velocity for the vehicle. The vehicle sensor data can include acceleration data along one or more axes. In several embodiments, the sensor data can include acceleration information in both a forward (x) and lateral (y) vector. The acceleration data can be processed to calculate the resultant change in velocity along one or more vectors in accordance with embodiments of the invention. By way of example, the resultant change in velocity along a forward (x) and lateral (y) vector (RESdvXY(xy)) can be calculated by:

RESdvXY(xy)=√{square root over (∫Xacceleration²+∫Yacceleration²)}

where Xacceleration is the measured acceleration along the forward vector and Yacceleration is the measured acceleration along the lateral vector. It should be noted that some (e.g. a subset) or all of the acceleration samples can be utilized to determine the resultant change in velocity as appropriate to the requirements of specific applications of embodiments of the invention.

The resultant change in velocity can be compared to the threshold data to determine if a crash has occurred. By way of example, if the resultant change in velocity is less than a threshold value then the event can be considered a non-crash and if the value is equal to or greater than a threshold value then it is considered a crash. Additionally, the characteristics of the vehicle can be provided as vehicle identification data and utilized in the crash analysis. In several embodiments, the vehicle identification data is used to select crash curve data for the specific vehicle identified from a set of crash curve data for a variety of vehicles. In a variety of embodiments, crash curve data is dynamically generated for the specific vehicle based on the vehicle identification data. In a number of embodiments, the weight of the vehicle can be utilized to determine the threshold value to determine if a crash event has occurred. Returning to the previous example, the weight of the vehicle could be utilized to recalculate the threshold value from the threshold described above. The threshold value can be any value in any units (such as meters per second or feet per second) as appropriate to the requirements of specific applications of embodiments of the invention.

In many embodiments, notification data can be generated when a crash has occurred. The notification data can be used to alert third party systems about a crash, solicit emergency services, and/or be provided to any of a variety of third-party systems as appropriate to the requirements of specific applications of embodiments of the invention. It should be noted that previously received data can be stored and utilized to refine the crash determination processes, including improving the determination of the threshold values based on the vehicle identification data and the calculation of the resultant change based on the vehicle sensor data.

Turning now to FIG. 5, a process for remote crash analysis in accordance with an embodiment of the invention is shown. The process 500 includes obtaining (510) data and calculating (512) resultant change data. When a threshold is reached (514), crash occurred data can be generated (516) and, in a number of embodiments, notification data can be provided (518).

Specific processes for remote crash analysis in accordance with embodiments of the invention are described above and shown with respect to FIG. 5; however, any number of processes, including those that provide alternative notifications to indicate a crash has occurred, can be utilized as appropriate to the requirements of a specific application in accordance with embodiments of the invention.

Filtering Noise

In a variety of embodiments, crash determination processes include filtering potential crash events to identify false positives. As described above, a variety of crash determination processes include calculating the resultant change in velocity and, based on that change in velocity, identifying if a crash has occurred. However, many events occurring within a vehicle can generate a resultant change in velocity sufficient to correspond to a crash event while no such event has actually occurred. For example, spirited driving on bumpy roads, driving over rumble strips commonly installed on the shoulders of roads, and the installation of the vehicle telematics unit can introduce noise into the measured sensor data and/or otherwise cause the sensors in the vehicle telematics unit to generate data indicative of a crash. In many embodiments, these false positive crash events exhibit a sinusoidal (e.g. oscillating) behavior that crosses zero in the measured data that can be decreasing in magnitude over time.

Turning now to FIGS. 7A and 7B, examples of acceleration data and resultant change data for various vehicle events are shown. Example 700 shown in FIG. 7A includes a forward acceleration curve 710, a lateral acceleration curve 712, a vertical acceleration curve 714, and the calculated resultant change 716. As illustrated in example 700, the forward acceleration curve 710 and the lateral acceleration curve 712 both exhibit oscillating behavior (e.g. sinusoidal behavior) that decreases in magnitude over time. As described above, this type of curve can be indicative of vehicle events that do not correspond to a crash event. Indeed, this particular example was generated based on driving on a bumpy road in a vehicle—a false positive for a crash event. By contrast, example 750 shown in FIG. 7B, includes a forward acceleration curve 760, a lateral acceleration curve 762, a vertical acceleration curve 764, and the calculated resultant change 766. In example 750, the forward acceleration curve 760 and the lateral acceleration curve 762 both exhibit a large change early in the event and quickly approach zero as opposed to oscillating over the duration of the event as in example 700. Example 750 was captured from a vehicle that was involved in an accident—a true crash event.

In order to filter false positive events to improve the accuracy of the crash determination processes, the crash determination processes can include calculating the absolute value of the integral and/or the summation of the acceleration samples in the forward vector added to the absolute value of the integral and/or the summation of the acceleration samples in the lateral vector. Returning to the examples shown in FIGS. 7A and 7B, the absolute value of the integral of the acceleration samples can be calculated by summing the values for the integral of the acceleration samples in the forward direction 710, 760 and taking the absolute value of that summation and adding it to the absolute value of the summation of the integral of the acceleration samples in the lateral direction 712, 762 respectively.

In several embodiments, the absolute speed change Asc for a potential crash event can be calculated using any of the following formulas:

Asc=|∫Xacceleration|+|∫Yacceleration|Asc=|∫Xacceleration|+|∫Yacceleration|+|∫Zacceleration|Asc=|∫Xacceleration+∫Yacceleration|Asc=|∫Xacceleration+∫Yacceleration+∫Zacceleration|Asc=|ΣXacceleration|+|ΣYacceleration|Asc=|ΣXacceleration|+|ΣYacceleration|+|ΣZacceleration|Asc=|ΣXacceleration+ΣYacceleration|Asc=|ΣXacceleration+ΣYacceleration+ΣZacceleration|

where Xacceleration is the measured acceleration along the forward vector, Yacceleration is the measured acceleration along the lateral vector, and Zacceleration is the measured acceleration along the vertical vector. It should be noted that some (e.g. a subset) or all of the acceleration samples can be utilized to determine the absolute speed change as appropriate to the requirements of specific applications of embodiments of the invention. Additionally, it should be noted, particularly in those embodiments employing a summation of the acceleration samples, that a fixed time period and/or a variable time period can be utilized in the summation. In this way, the time period over which the summation of the acceleration samples can be utilized to optimize the calculation of the absolute speed change based on the characteristics of the speed change. For example, if the acceleration curve for a first time period is relatively flat, the summation for the first time period can be for all of the acceleration samples over the first time period. If, over a second time period, the acceleration curve exhibits a strong oscillating behavior, the second time period can be calibrated to sum the acceleration samples in concert with the peaks and curves in the acceleration curve in the oscillating portion. In this way, a more accurate summation of the oscillating portion of the acceleration curve can be calculated. In this way, an approximation to the integral of the acceleration curve can be calculated without the overhead associated with the computation of the integral.

The absolute speed change can be compared to a speed change threshold to determine if a crash event has occurred. By way of example, if the resultant change in velocity exceeds a threshold value while the absolute speed change is below a threshold value then the event can be considered a false positive and thereby a non-crash event. Similarly, if both calculated values exceed their respective threshold values then it is considered a crash event. In many embodiments, the threshold value for the absolute speed change is based on the resultant change data. That is, when the absolute speed change is within a threshold value of the resultant change data a crash event has occurred and crash occurred data describing the crash can be generated. Additionally, the characteristics of the vehicle can be provided as vehicle identification data and utilized in the determination of the absolute speed change threshold. For example, particular vehicles may have characteristics that tend to introduce noise into the sensor data and the absolute speed change threshold for those vehicles may be higher than for other vehicles. Particular vehicles can be identified by any criteria, such as a VIN, utilizing techniques similar to those described above. In many embodiments, the absolute speed change and/or resultant change for an event is stored in a historical database for a number of vehicles and (potential) crash events. This historical database can then be utilized to identify threshold values and/or crash curves to facilitate the determination of crash events as described above.

Turning now to FIG. 6, a process for filtering noise in a crash analysis in accordance with an embodiment of the invention is shown. The process 600 includes obtaining (610) resultant change data and calculating (612) absolute speed change data. When an oscillating event is detected (614), the obtained data can be stored (620). When an oscillating event is not detected (614), crash occurred data can be generated (616) and, in a number of embodiments, notification data can be provided (618).

Specific processes for crash analysis with noise filtering in accordance with embodiments of the invention are described above and shown with respect to FIG. 6; however, any number of processes, including those that filter noise in the first stage of the crash analysis as described above, can be utilized as appropriate to the requirements of a specific application in accordance with embodiments of the invention.

Although the present invention has been described in certain specific aspects, many additional modifications and variations would be apparent to those skilled in the art. In particular, any of the various processes described above can be performed in alternative sequences and/or in parallel (on the same or on different computing devices) in order to achieve similar results in a manner that is more appropriate to the requirements of a specific application. It is therefore to be understood that the present invention can be practiced otherwise than specifically described without departing from the scope and spirit of the present invention. Thus, embodiments of the present invention should be considered in all respects as illustrative and not restrictive. It will be evident to the person skilled in the art to freely combine several or all of the embodiments discussed here as deemed suitable for a specific application of the invention. Throughout this disclosure, terms like “advantageous”, “exemplary” or “preferred” indicate elements or dimensions which are particularly suitable (but not essential) to the invention or an embodiment thereof, and may be modified wherever deemed suitable by the skilled person, except where expressly required. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their equivalents. 

1. A vehicle telematics device comprising a processor and a memory storing a crash determination application, the vehicle telematics device coupled to at least one sensor having an accelerometer, wherein the processor of the vehicle telematics device, on reading the crash determination application, is directed to: obtain sensor data from the at least one sensor installed in a vehicle; calculate peak resultant data based on the sensor data, where the peak resultant data describes the acceleration of the vehicle over a first time period; generate crash score data based on the peak resultant data and a set of crash curve data for the vehicle, where the crash score data describes the likelihood that the vehicle was involved in a crash based on the characteristics of the vehicle and the sensor data; calculate absolute speed change data based on the sensor data; identify a false positive non-crash event when an oscillating event is detected that decreases in magnitude over time; and provide the obtained sensor data to a remote server system when the crash score data exceeds a crash threshold and when a false positive non-crash event is not identified.
 2. The vehicle telematics device of claim 1, wherein the crash curve data is based on vehicle data comprising a vehicle identification number associated with the vehicle.
 3. The vehicle telematics device of claim 1, wherein the crash curve data is dynamically determined based on vehicle data describing a weight of the vehicle.
 4. The vehicle telematics device of claim 3, wherein the at least one sensor comprises a weight sensor.
 5. The vehicle telematics device of claim 1, further comprising a communications interface, wherein the vehicle telematics device obtains the sensor data using the communications interface.
 6. The vehicle telematics device of claim 1, wherein the set of crash curve data is provided by the remote server system.
 7. The vehicle telematics device of claim 1, wherein the absolute speed change data is calculated by taking the absolute value of the integral of the sensor data indicating acceleration data in a forward vector.
 8. The vehicle telematics device of claim 1, wherein the absolute speed change data is calculated by taking the absolute value of the integral of the sensor data indicating acceleration data in a lateral vector.
 9. The vehicle telematics device of claim 1, wherein the crash score data is generated by: calculating peak resultant data based on the obtained sensor data; and calculating the crash score data based on a duration of time in which the peak resultant data exceeds the crash curve data.
 10. The vehicle telematics device of claim 1, wherein the processor of the vehicle telematics device, on reading the crash determination application, is further directed to: calculate resultant velocity change based on the obtained sensor data and the vehicle identification data; and generate crash occurred data when the resultant velocity change exceeds a first threshold value and when the absolute speed change data is below a second threshold value.
 11. A method for determining if a vehicle has been involved in a crash, comprising: obtaining, by a telematics device, sensor data from the at least one sensor installed in a vehicle, wherein the at least one sensor has an accelerometer; calculating, by the telematics device, peak resultant data based on the sensor data, where the peak resultant data describes the acceleration of the vehicle over a first time period; generating, by the telematics device, crash score data based on the peak resultant data and a set of crash curve data for the vehicle, where the crash score data describes the likelihood that the vehicle was involved in a crash based on the characteristics of the vehicle and the sensor data; calculating, by the telematics device, absolute speed change data based on the sensor data; identifying, by the telematics device, a false positive non-crash event when an oscillating event is detected that decreases in magnitude over time; and providing, by the telematics device, the obtained sensor data to a remote server system when the crash score data exceeds a crash threshold and when a false positive non-crash event is not identified.
 12. The method of claim 11, wherein the crash curve data is based on vehicle data comprising a vehicle identification number associated with the vehicle.
 13. The method of claim 11, further comprising dynamically determining, by the telematics device, the crash curve data based on vehicle data describing a weight of the vehicle.
 14. The method of claim 13, wherein the at least one sensor comprises a weight sensor.
 15. The method of claim 11, further comprising obtaining, by the telematics device, the sensor data using a communications interface of the telematics device.
 16. The method of claim 11, wherein the set of crash curve data is provided by the remote server system.
 17. The method of claim 11, wherein calculating the absolute speed change data comprises calculating the absolute speed change data by taking the absolute value of the integral of the sensor data indicating acceleration data in a forward vector.
 18. The method of claim 11, wherein calculating the absolute speed change data comprises calculating the absolute speed change data by taking the absolute value of the integral of the sensor data indicating acceleration data in a lateral vector.
 19. The method of claim 11, wherein generating the crash score data comprises: calculating peak resultant data based on the obtained sensor data; and calculating the crash score data based on a duration of time in which the peak resultant data exceeds the crash curve data.
 20. The method of claim 11, further comprising: calculating, by the telematics device, resultant velocity change based on the obtained sensor data and the vehicle identification data; and generating, by the telematics device, crash occurred data when the resultant velocity change exceeds a first threshold value and when the absolute speed change data is below a second threshold value. 